Video encoder, a video decoder and corresponding methods with improved block partitioning

Abstract

The present disclosure provides an encoding apparatus and a decoding apparatus, as well as an encoding method and a decoding method. In particular, the present disclosure relates to block partitioning and signaling the partitioning parameters in a bitstream. An override flag in a slice header indicates whether or not a block is to be partitioned according to a first partition constraint information. The override flag is included in the bitstream and the block is partitioned accordingly.

The invention claimed is: 
     
       1. A method for decoding a video bitstream implemented by a decoding device, comprising:
 obtaining an override flag from the video bitstream, wherein the video bitstream comprises a picture header of a picture, data representing a slice partitioned from the picture, and a sequence parameter set (SPS), and wherein the override flag indicates whether first partition constraint information is present in the picture header; 
 obtaining a value of the first partition constraint information for the slice from the picture header when a value of the override flag is an overriding value; 
 partitioning a block of the slice into a plurality of sub-blocks according to the obtained value of the first partition constraint information; 
 partitioning the block of the slice into a plurality of sub-blocks according to a default value of the first partition constraint information when the value of the override flag is not the overriding value, wherein the default value of the first partition constraint information is a value of second partition constraint information from the SPS; and 
 reconstructing the block of the slice by reconstructing the plurality of sub-blocks. 
 
     
     
       2. The method of  claim 1 , wherein the second partition constraint information comprises one or more of partition constraint information for blocks in the slice coded in an intra mode, or partition constraint information for blocks in the slice coded in an inter mode. 
     
     
       3. The method of  claim 1 , wherein the second partition constraint information comprises partition constraint information for luma blocks in the slice, or partition constraint information for chroma blocks in the slice. 
     
     
       4. The method of  claim 1 , wherein the obtaining the override flag from the video bitstream comprises obtaining the override flag from the picture header. 
     
     
       5. A method for encoding a picture into a video bitstream implemented by an encoding device, comprising:
 encoding a value of first partition constraint information into a picture header of the video bitstream when a value of an override flag is an overriding value; 
 partitioning a block of a slice partitioned from the picture into a plurality of sub-blocks according to the value of the first partition constraint information; 
 encoding the override flag with the overriding value into the video bitstream; 
 partitioning the block of the slice into a plurality of sub-blocks according to a default value of the first partition constraint information when the value of the override flag is not the overriding value, wherein the default value of the first partition constraint information is a value of second partition constraint information; encoding the value of the second partition constraint information into a sequence parameter set (SPS) of the video bitstream; and encoding the override flag with a value different from the overriding value into the video bitstream. 
 
     
     
       6. The method of  claim 5 , wherein the second partition constraint information comprises partition constraint information for blocks in the slice that are coded in an intra mode, or partition constraint information for blocks in the slice that are coded in an inter mode. 
     
     
       7. The method of  claim 5 , the second partition constraint information comprises partition constraint information for luma blocks in the slice, or partition constraint information for chroma blocks in the slice. 
     
     
       8. The method of  claim 5 , wherein the override flag is in the picture header. 
     
     
       9. A non-transitory computer-readable storage medium for storing data associated with a video, comprising:
 a video bitstream stored in non-transitory computer-readable storage medium, wherein the video bitstream comprises a picture header of a picture, and a sequence parameter set (SPS) of the video bitstream, wherein the video bitstream further comprises an override flag, and wherein the override flag indicates whether first partition constraint information is present in the picture header, and the first partition constraint information is for overriding second partition constraint information in the SPS. 
 
     
     
       10. A decoder, comprising:
 one or more processors; and 
 a non-transitory computer-readable storage medium coupled to the one or more processors and storing programming instructions for execution by the one or more processors, wherein the programming instructions, when executed by the one or more processors, configures the decoder to carry out operations comprising:
 obtaining an override flag from the video bitstream, wherein the override flag indicates whether first partition constraint information is present in a picture header of the video bitstream; 
 when a value of the override flag is an overriding value, obtaining first partition constraint information for the slice from the picture header; 
 partitioning a block of the slice into a plurality of sub-blocks according to obtained value of the first partition constraint information; 
 when the value of the override flag is not the overriding value, partitioning the block of the slice into a plurality of sub-blocks according to a default value of the first partition constraint information, wherein the default value of the first partition constraint information is a value of second partition constraint information from a sequence parameter set (SPS) of the video bitstream; and 
 reconstructing the block of the slice by reconstructing the plurality of sub-blocks. 
 
 
     
     
       11. An encoder, comprising:
 one or more processors; and 
 a non-transitory computer-readable storage medium coupled to the one or more processors and storing programming instructions for execution by the one or more processors, wherein the programming instructions, when executed by the one or more processors, configures the encoder to carry out operations comprising:
 encoding a value of first partition constraint information into a picture header of a video bitstream when a value of an override flag is an overriding value; 
 partitioning a block of a slice partitioned from a picture into a plurality of sub-blocks according to the value of the first partition constraint information; 
 encoding the override flag with the overriding value into the video bitstream; 
 partitioning the block of the slice into a plurality of sub-blocks according to a default value of the first partition constraint information when the value of the override flag is not the overriding value, wherein the default value of the first partition constraint information is a value of second partition constraint information; 
 encoding the value of the second partition constraint information into a sequence parameter set (SPS) of the video bitstream; and 
 encoding the override flag with a value different from the overriding value into the video bitstream.